Railway road beds must be capable of supporting extremely heavy rolling stock. Road beds have traditionally included closely spaced railroad ties for supporting the railroad rails. The ties in turn are supported by ballast comprising essentially debris-free rock through which rain water can quickly drain.
Maintenance of the ballast in a railway road bed is of primary concern in extending the usefulness of the railway road bed. The ballast must be periodically cleaned to remove mud and debris that accumulates in the ballast and which would otherwise block the drainage of rain water from the railway road bed. Additionally, the quality of a railroad track is closely related to the levelness of the track. The ballast must be periodically tamped or blown underneath the railroad ties to true the level of the track.
Maintenance of a railway road bed by cleaning or tamping the track bed often requires the addition of ballast to the bed. Adding ballast to the track bed by conventional means is a time-consuming, labor intensive, and logistically difficult operation requiring several different crews and the scheduling of several different pieces of maintenance equipment. Additional ballast is initially deposited along the railroad track bed by a ballast car having hoppers for transporting and operating at the appropriate point to deposit ballast. A second crew then passes along the railroad track with a ballast regulating car that distributes the ballast on the railway track bed and picks up excess ballast. Finally, in situations where the excess ballast is too much to reclaim, or is distributed outside the reach of the regulating and reclaiming car, ballast is formed into windrows spaced apart from the railway road bed.
Ballast is discharged from the ballast-carrying hopper cars by a crew member who walks beside the ballast cars. The crew member uses a long metal lever that is placed in a tube attached to the discharge door to be opened or closed. The crew member, while walking along side the moving ballast car, pushes the lever up or down to pivot the door open or closed. The doors are generally oriented directly above a rail and include a chute or chutes that can be pivoted to either side of the rail for depositing ballast to the field side or the gauge side of the rail.
Frequently, when a crew member moves the lever back to its original position to close a discharge door, pieces of ballast become wedged in the opening between the hopper discharge gate and the discharge door. The crew member must push the lever quickly up and down moving the discharge door just enough to free the ballast and close the door before any more ballast becomes wedged. As a crew member works to unblock the discharge door excess ballast may be discharged resulting in the waste of some ballast. Moreover, pushing the lever up and down is physically demanding and the crew member must pay strict attention to safety as he walks along side the moving train. Operation of the ballast discharge doors is particularly dangerous when a hopper door must be quickly closed prior to the ballast car transmitting across a bridge, switch track or other obstacles.
It will also be appreciated that clouds of dust often obscure the ballast car and make an accurate calculation of the amount of ballast discharged through any hopper door over a particular section of rail very difficult to determine. The clouds of dust and noise of ballast discharging make it difficult for crew members to communicate with one another. The inability to readily communicate leads to confusion and inefficient use of manpower.
A railway maintenance system that could deposit ballast, distribute the ballast, and reclaim excess ballast, including excess ballast that would otherwise have to be formed into windrows, would provide decided advantages to the railroad maintenance industry in terms of scheduling, manpower, and ballast wastage. Moreover, a ballast maintenance system that, with limited manpower, could automatically calculate the amount of ballast necessary to maintain the railway, discharge that ballast through remote control of motorized ballast discharge doors, and automatically pinpoint any problems encountered during the process, would greatly enhance the safety and efficiency of railroad ballast distribution operations.